Door closer

ABSTRACT

A door closer for affording a controlled closing movement to a door including a return spring, an oil hydraulic piston and cylinder means, and a valve for generating a damping force when the door closers, said valve comprises a movable valve member for regulating oil flow through the valve, and a bimetal element connected with the movable valve member in response to the change in the temperature thereby attaining a substantially constant closing speed of the door irrespective to the change in the temperature.

United States Patent [191 Nakane et a1.

[ 1 Oct. 21, 1975 DOOR CLOSER Inventors: Sunao Nakane; Kiyoyasu Wake,

both of Tokyo, Japan Assignees: Miwa Lock Co., Ltd; Showa Seisakusho C0., both of Tokyo, Japan Filed: Jan. 2, 1975 Appl. No.: 538,007

Related US. Application Data Continuation of Ser. No. 373.152, June 25, 1973,

abandoned.

Foreign Application Priority Data June 27, 1972 Japan 47-75098 Int. Cl? EOSF 3/14; EOSF 3/22 Field of Search 16/58, 52, DIG. 9, DIG. 21, 16/D1G. 17, DIG. 23, 48.5; 137/468;

References Cited UNITED STATES PATENTS Hapgood 188/277 Beecher 137/468 X 2,683,505 7/1954 Girard... 188/277 3,006,441 10/1961 Bliven et 111.... Wi t/I774 3,497,904 3/1970 Meravo... 16/52 3,532,195 10/1970 Miller 188/277 3,791,494 2/1974 McNally. 188/277 FOREIGN PATENTS OR APPLlCA'llUNS 643,380 9/1951) United Kingdom... INK/277 1,067,393 1/1954 France H 188/277 1,131,684 10/1956 France... 188/277 1,054,788 4/1959 German IRS/Z77 Primary Examiner-Werner H. Schroeder Assistant Emmmer VWiyne L. Shedd Attorney. Agent, or Firm Christens'en. ()Connor, Garrison & Havelka [57] ABSTRACT A door closer for affording a controlled closing movement to a door including a return spring, an oil hydraulic piston and cylinder means, and a valve for generating a damping force when the door closers, said valve comprises a movable valve member for regulating oil flow through the valve, and a himetal element connected with the movable valve member in re sponse to the change in the temperature thereby attaining a substantially constant closing speed of the door irrespective to the change in the temperature.

5 Claims, 10 Drawing Figures U.S. Patent Oct. 21, 1975 Sheet 1 of3 3,913,170

US. Patent Oct.21, 1975 Sheet2of3 3,913,170

US. Patent 0a. 21, 1975 Sheet 3 of3 3,913,170

DOOR CLOSER This is a continuation of application Ser. No. 373,152, filed June 25, 1973, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a door closer for closing a door automatically.

A door closer is known to public for closing a door automatically, and usually, it comprises a link arm for connecting the door closer with a door or with a stationary part of a building. a return spring for affording an actuating force to the door closer, and a clamping device for affording a suitable closing speed to the door.

An oil hydraulic cylinder piston mechanism is commonly used as the clamping device of the door closer, in which oil is forced to flow through an enclosed passage including an orifice and, the damping force is given by the resistance of oil flowing through the orifree.

In case of a door closer of the type, the damping force is affected remarkably by the outside or circumferential temperature, since the viscosity of oil varies in response to the temperature and the oil flow through the orifice varies in accordance with the viscosity. Thus, when the temperature is high as in the summer season the door closes more rapidly than when the temperature is low as in the winter season.

A speed regulating valve for adjusting the closing speed of the door which enables manual adjustment when it requires has been proposed, but it is very inconvenient to adjust each of a large number of door closers as required. Moreover, the regulating valve is arranged to contact with oil directly, and a manual actuating member extends outside through the housing of the door closer, thus, there remains a sealing problem and a wear problem at a position where the rotatable or slidable actuating member extending through the housing. Therefore, the door closer having such manual regulating valve will not work satisfactorily for a very long service life required for a door closer.

BRIEF SUMMARY OF THE INVENTION An object of this invention is to provide a door closer affording substantially constant door closing speed regardless of the change in the circumferential temperature thus preventing the troublesome manual adjustment which otherwise required for user of the door closer.

A further object of this invention is to provide a door closer which enables to omit a door closing speed regulating valve having an oil seal which tends to cause oil leakage especially when the regulating operation is performed and an actuating member of the valve wears.

Another object of this invention is to provide a damping device for a door closer having a very simple and compact construction and being adapted to be easily composed into the hitherto used door closer by a small modification and effective to afford substantially constant and suitable door closing speed regardless of the circumferential temperature.

The door closer of this invention comprises an oil hydraulic piston and cylinder means adapted to cause oil flow in an enclosed space formed within the housing of the door closer when a piston of said piston and cylinder means moves in one direction, a valve for controlling said oil flow, the movable member of said valve being connected with a bimetal element so as to move automatically in response to the change in circumferential temperature thereby controlling the valve opening automatically.

The valve for controlling the oil flow of this invention may comprise a through hole formed in one of the end plates closing one end of the cylinder and communicating with the other end of the cylinder, a movable valve plate slidably engaging with the inner serface of said end plate for cooperating with the inner periphery of said through hole, and a bimetal element one end of which being connected with the valve plate and the other end of which being secured to the end plate.

The through hole may extend axially the valve plate having a generally flat surface slides along the inner surface of a plate-like formed end closure member for adjusting the opening area of the valve. The valve for controlling oil flow of this invention may comprise an opening disposed at one end of the cylinder and on the inner cylindrical wall thereof, an arcuate valve plate urged against said cylindrical wall slidably in circumferential direction, and a bimetal element one end of which being connected pivotally to the valve plate and the other end of which being secured to an end plate closing said one end of the cylinder.

Preferably, the bimetal element is formed as generally U-shaped plate-like member.

BRIEF DESCRIPTION OF DRAWINGS In order to make this invention more clearly understood, two embodiments of this invention are shown in the accompanying drawings, in which:

FIG. I is a longitudinal cross section of an oil hydraulic damping device adapted to be composed in a door closer of this invention.

FIG. 2 is a cross section along line AA of FIG. I.

FIG. 3 is a cross section along line 8-8 of FIG. 2.

FIG. 4 is a cross section along line CC of FIG. 2.

FIG. 5 is an enlarged view of a portion of FIG. 2.

FIG. 6 is a longitudinal cross section of another oil hydraulic damping device of a door closer of this invention.

FIG. 7 is a cross section along line DD of FIG. 6.

FIG. 8 is a diagrammatic drawing showing the relative position between the valve plate and the opening.

FIG. 9 is a drawing similar to FIG. 8, but showing the position when the oil flow passage opens widely.

FIG. 10 is an exploded perspective view of the bimetal element and the valve plate of FIGS. 6-9.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an oil hydraulic clamping device adapted to be composed in a door closer of this invention. A return spring for affording the actuating force to the door closer, a link mechanism for connecting the door closer with a door or with a building, and a housing for receiving the mechanism and protecting it from dust or moisture are omitted from the drawing. In the drawing, a piston 3 is slidably received in an inner cylinder 2 defining first and second chambers therein. Cylinder 2 is enclosed coaxially within an outer cylinder or a housing 7, the inside of which is filled with oil 1. A piston rod 11 secured to the pist 1n 3 extends rightward in FIG. I to the outside of the housing. 9 is a rod guide and closes the right end of the cylinder 2, and 10 is an oil seal. The outer end of the piston rod 11 is connected with a link mechanism (not shown) and normally urged leftward by a return spring (not shown).

The piston 3 has a plurality of axial through holes 4. A plate valve 6 cooperates with the holes 4 and urged in its closed position by a Belleville spring 5. These members 4, 5 and 6 form a check valve which opens when the piston 3 moves rightward in FIG. 1 and allows relatively free oil flow across the piston 3. But the check valve closes when the piston moves leftward. Between the inner and the outer cylinders 2 and 7 a space 8 is formed which acts as an oil passage communicating with the both ends of the cylinder 2. An oil passage 13 having a check valve 12 and an oil passage 14 communicating the space 8 with a clearance formed between the rod guide 9 and the oil seal are disposed in the rod guide 9. A small hole or holes 15 are formed in cylindrical wall of the cylinder 2 at the mid portion thereof as shown in the drawing. The left end of the cylinder 2 is closed by an end closure plate 16, and a space 17 is formed between the end plate 16 and the left end of the outer cylinder 7. The space 17 is communicated with the space 8. A strut 18 is disposed on the inner side ofthe plate 16 as shown in FIGS. 2 and 3 for securing one end of a U-shaped plate-like bimetal element 19. The other end of the bimetal 19 is pivotally con nected with a valve plate 20 acting as a throttle valve. A through hole 23 is formed in the end plate 16 the inner end of which constitutes a stationary valve member cooperating with the valve plate 20 which slides on the inner surface of the end plate 16. As shown in FIGS. 4 and 5, a fan-shaped recess 24 is formed at the inner end of the through hole 23. A further check valve comprising a through hole 22 and a ball 21 is disposed in the end plate 16. In FIG. 5, are recesses formed in the periphery of the valve plate 20 for engaging with protrusions (not shown) formed at the lower end (in FIG. 4) of the bimetal 19.

The oil damper acts as follows. When the door is moved to open, the piston 3 moves rightward in FIG. 1. The check valve 6 opens, and oil in the right side of the piston 3 flows into the left side of the piston thus affording relatively small resistance to the door. At the same time, the check valve 21 opens, and a quantity of oil corresponding to the movement of the piston rod 11 drawn out from the cylinder 2 flows into the left side of the piston 3.

When the door is released, the return spring of the door closer tends to move the piston 3 leftward. The check valves 6 and 21 close, and the check valve 12 opens for supplying oil to the right side of the piston 3 through the passages 14 and 13. The oil in the left side of the piston 3 flows to the space 8 through the damping force generating hole 23 and the small holes 15 and, a damping force is generated against the movement of the piston 3, thereby the door moves slowly. In the midstroke of the closing movement of the door, the small holes 15 will be covered by the piston 3, thereafter, the oil in the left side of the piston 3 is forced to flow only through the hole 23 and, a large damping force is generated and the door moves very slowly.

In the case when the room temperature is high and the oil viscosity is low, the bimetal l9 and the valve 20 take the position shown in the solid line in FIG. 2, but when the room temperature descends, the bimetal 19 takes the position shown in the chain line in FIG. 2 and, the valve 20 moves in the arrow a direction in FIGS. 4 and 5 affording a larger valve opening area. Thus, the

bimetal l9 and the valve act to change the valve open ing area in response to the change in the room tempe rature. The configuration of the recess 24 formed in the upper end of the hole 23 and the characteristics of the bimetal 19 can be suitably determined to provide a substantially constant damping force or the door closing speed regardless of the room temperature.

At that time, the valve 20 is forced to contact with the inner surface of the end plate 16 and with the periphery of the hole 23 by oil pressure in the left side of the piston 3, thereby thefluctuation in the damping force will not occur and, the valve operates stably.

The oil damper can afford a substantially constant damping force regardless of the change in the room temperature, thus, the door closer of this invention can avoid such deficiencies as a remarkable change in the door closing speed between winter and summer. The construction of the oil damper is very simple and, it can be manufactured at a low cost. Since the adjustment is performed automatically, it is not necessary to adjust from the outside, thus, the door closer is very convenient to handle.

FIGS. 6-10 show another embodiment of this invention. Referring especially FIG. 6, the door closer comprises a housing 25 having a through bore or cylinder 2. A cup-shaped piston 3 is slidably received in the cylinder 2, defines first and second chambers therein and is urged rightward in FIG. 6 by a return spring 25 acting between an end cap 34 closing the left end of the cylinder 2 and the inner base of the cup of the piston 3. A check valve 27 is disposed in a through hole 26 formed in the piston 3. On the side wall of the cup, there provided a rack 29 for engaging with a pinion 30 rotatably supported in the housing 25, and the rotation of the pinion 30 is transmitted to a door through a suitable link mechanism (not shown). The cylinder 2 is filled with oil, and an oil passage 31 formed in the wall of the housing 25 connects the both ends of the cylinder 2 as shown in the drawing. A manual regulating valve 32 is arranged in the passage 31 for restricting oil flow through the passage. At the right end of the cylinder 2 the passage 31 opens at the cylindrical outer peripheral surface of an annular recess 40 in the wall of the cylinder 2, and the opening 31 of the same acts as a damping force generating opening which will be hereinafter described in detail. The right end of the cylinder 2 is closed by an end cap 33 and an end plate 35. As shown in FIGS. 7 and 10, a bimetal element 19 having configuration similar to that of the first embodiment is secured to the plate 35 by utilizing an attachment l8 and screws. A valve plate 20 having an arcuate outer surface is connected to the bimetal element 19 and cooperates with the damping force generating opening which is shown by numeral 31' in FIGS. 8-10. The valve plate 20 can slide circumferentially along the inner surface of the cylindrical recess when reciprocated by the element 19. In the drawings, 36 and 36 are pins supporting the valve plate 20. The pins enable smooth movement of the plate 20 and avoid any undersirable force which might act on the bimetal element 19. Also, the plate 20 has spaced, parallel arms 42 thereon, and the connection between the plate and the element 19 is achieved by inserting the free end of the element in trapezoidally cross sectioned recesses 37 in the ends of the arms (FIG. 10). Because of the trapezoidal cross section of the recesses 37, the element can pivot in relation to the plate when the element is undergoing deflection. The numeral 38 shows a locating pin for the end plate 35. As shown in FIGS. 8 and 9, the nose edge of the valve plate forms an oblique line relative to the direction of movement (horizontal in the drawings) of the valve 20, which enables a fine or an incremental non-arithmetic adjustment.

When a door connected with the door closer is opened, the pinion rotates and the piston 3 moves leftward in FIG. 6 and the spring 28 is compressed. The check valve 27 opens and, oil flows from the left side to the right side of the piston 3 showing relatively small resistance to the opening movement of the door. When the door is released to close, the compressed spring 28 moves the piston 3 rightward, and the check valve 27 closes. Oil in the right side of the piston 3 flows through the oil passage 31 to the left side of the piston 3. The valve plate 20 acts to control the valve opening and generates a sufficient damping force against the movement of the piston 3.

When the room temperature is high, and the viscosity of oil is low, the bimetal 19 takes the position shown in solid line in FIG. 7. When the room temperature is low, the bimetal 19 bends and takes the position shown in chain line in FIG. 7. The valve 20 moves from FIG. 8 to FIG. 9. Thus, the valve opening increases in response to the decrease in the room temperature, thereby the increase in the damping force due to increase in the oil viscosity can be compensated.

Therefore, by determining the dimensions of the opening of the oil passage 31 and the characteristics of the bimetal element 19 suitably, it is possible to attain a substantially constant damping force irrespective to the change in the room temperature.

The manual regulating valve 32 is arranged to perform the initial adjustment, and it is not necessary to manipulate it in use and, therefore, it is possible to omit the valve 32.

Although the embodiment does not show the small hole 15, it is possible to provide a suitable small hole connecting the oil passage 31 with the inside of the cylinder 2 and being closed by the piston 3 at the midstroke thereof.

As described above, the door closer of this invention can close a door at a suitable speed regardless of the change in the room temperature, and enables to omit a manual adjusting valve which is very troublesome to handle and which has a very serious problem in preventing oil leakage.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as some modifications may be obvious to those skilled in the art.

What is claimed is:

1. In a door closer, a housing having a cylinder formed therein and a piston slidably engaged in the cylinder to reciprocate axially thereof and define first and second chambers therein, means yieldably biasing the piston in one axial direction of the cylinder, means for interconnecting the piston with the door so that during opening of the door said means for interconnecting moves the piston in the other axial direction of the cylinder against the bias thereon, and means for damping the reciprocation of the piston in the one axial direction of the cylinder under the bias thereon when the door is released, including a hydraulic fluid charge in the cylinder, means defining a first fluid flow path and a second fluid flow path between said first and second chambers, check valve means in the first fluid flow path whereby the fluid can flow therethrough only from the second chamber to the first chamber, when the piston is reciprocated in the other axial direction of the cylin der, and throttle valve means in the second fluid flow path whereby the fluid flow from the first chamber to the second chamber is throttled at a variable rate when the piston is reciprocated in the one axial direction of the cylinder, said second fluid flow path including an outlet for the fluid in one wall of said first chamber, said throttle valve means including a bimetallic thermostatic element which is cantilevered into the first chamher from a point within the housing, an arcuate valve closure member, and means slidably mounting the arcuate valve closure member in the housing adjacent the outlet so that the closure member can slide circumferentially in relation to the outlet and can overlap the outlet to a variable extent, the free end of the bimetallic element being relatively pivotally interconnected with the arcuate value closure member rendering said arcuate valve closure member self-aligning with the wall surrounding said outlet so that deflection of the element in response to temperature variations in the fluid charge causes the closure member to move circumfer' entially in relation to the outlet and thereby to vary the extent of its overlap with the outlet, but pressure differentials across the closure member do not cause counter deflections in the element which could distort the shape of the element.

2. The door closer according to claim 1 wherein the rim of the outlet and the closure member are slidably engaged and are adapted in relation to one another so that they define an opening for passage of the fluid which varies non-arithmetically in area as the closure member reciprocates in relation to the outlet.

3. The door closer according to claim 2 wherein the outlet is defined by the end opening of a through-bore in the housing, and said through-bore has a shallow, laterally projecting recess therein at the end opening, which recess has a generally V-shaped plan configuration in the plane of the opening, and is in part covered by the closure member.

4. The door closer of claim 1 wherein the first flow path is through said piston.

5. The door closer of claim 1 wherein said valve closure member is slidable circumferentially along the inner surface of a cylindrical recess, said outlet opening through said surface. 

1. In a door closer, a housing having a cylinder formed therein and a piston slidably engaged in the cylinder to reciprocate axially thereof and define first and second chambers therein, means yieldably biasing the piston in one axial direction of the cylinder, means for interconnecting the piston with the door so that during opening of the door said means for interconnecting moves the piston in the other axial direction of the cylinder against the bias thereon, and means for damping the reciprocation of the piston in the one axial direction of the cylinder under the bias thereon when the door is released, including a hydraulic fluid charge in the cylinder, means defining a first fluid flow path and a second fluid flow path between said first and second chambers, check valve means in the first fluid flow path whereby the fluid can flow therethrough only from the second chamber to the first chamber, when the piston is reciprocated in the other axial direction of the cylinder, and throttle valve means in the second fluid flow path whereby the fluid flow from the first chamber to the second chamber is throttled at a variable rate when the piston is reciprocated in the one axial direction of the cylinder, said second fluid flow path including an outlet for the fluid in one wall of said first chamber, said throttle valve means including a bimetallic thermostatic element which is cantilevered into the first chamber from a point within the housing, an arcuate valve closure member, and means slidably mounting the arcuate valve closure member in the housing adjacent the outlet so that the closure member can slide circumferentially in relation to the outlet and can overlap the outlet to a variable extent, the free end of the bimetallic element being relatively pivotally interconnected with the arcuate value closure member rendering said arcuate valve closure member selfaligning with the wall surrounding said outlet so that deflection of the element in response to temperature variations in the fluid charge causes the closure member to move circumferentially in relation to the outlet and thereby to vary the extent of its overlap with the outlet, but Pressure differentials across the closure member do not cause counter deflections in the element which could distort the shape of the element.
 2. The door closer according to claim 1 wherein the rim of the outlet and the closure member are slidably engaged and are adapted in relation to one another so that they define an opening for passage of the fluid which varies non-arithmetically in area as the closure member reciprocates in relation to the outlet.
 3. The door closer according to claim 2 wherein the outlet is defined by the end opening of a through-bore in the housing, and said through-bore has a shallow, laterally projecting recess therein at the end opening, which recess has a generally V-shaped plan configuration in the plane of the opening, and is in part covered by the closure member.
 4. The door closer of claim 1 wherein the first flow path is through said piston.
 5. The door closer of claim 1 wherein said valve closure member is slidable circumferentially along the inner surface of a cylindrical recess, said outlet opening through said surface. 